[PATCH net-next v4 2/2] of: net: fix of_get_mac_addr_nvmem() for non-platform devices

[Benjamin Herrenschmidt]

On Mon, 2021-04-12 at 19:47 +0200, Michael Walle wrote:
> 
>  /**
>   * of_get_phy_mode - Get phy mode for given device_node
> @@ -59,15 +60,39 @@ static int of_get_mac_addr(struct device_node *np, const char *name, u8 *addr)
>  static int of_get_mac_addr_nvmem(struct device_node *np, u8 *addr)
>  {
>         struct platform_device *pdev = of_find_device_by_node(np);
> +       struct nvmem_cell *cell;
> +       const void *mac;
> +       size_t len;
>         int ret;
>  
> -       if (!pdev)
> -               return -ENODEV;
> +       /* Try lookup by device first, there might be a nvmem_cell_lookup
> +        * associated with a given device.
> +        */
> +       if (pdev) {
> +               ret = nvmem_get_mac_address(&pdev->dev, addr);
> +               put_device(&pdev->dev);
> +               return ret;
> +       }
> +

This smells like the wrong band aid :)

Any struct device can contain an OF node pointer these days.

This seems all backwards. I think we are dealing with bad evolution.

We need to do a lookup for the device because we get passed an of_node.
We should just get passed a device here... or rather stop calling
of_get_mac_addr() from all those drivers and instead call
eth_platform_get_mac_address() which in turns calls of_get_mac_addr().

Then the nvmem stuff gets put in eth_platform_get_mac_address().

of_get_mac_addr() becomes a low-level thingy that most drivers don't
care about.

Cheers,
Ben.